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bioRxiv · 10.1101/2025.11.25.690615

Deep-brain thermo-endomicroscopy

Imamura, R.·Nakane, Y.·Kataoka, N.·Abe, H.·Ohshima, T.·Sotoma, S.·Sugi, T.
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Abstract

Subtle deviations in biophysical parameters, particularly temperature, within deep-brain regions exert substantial effects on whole-body homeostasis and metabolism. However, the underlying mechanisms remain poorly understood because cellular-resolution measurements of these parameters in the deep brain have been technically inaccessible. Here, we present a lensless fiber-optic quantum-sensing endomicroscopy that enables cellular-resolution temperature mapping in the mouse deep brain. A microwire-coupled, lensless fiber bundle permits simultaneous temperature readout from optically detected magnetic resonance spectra of >50 fluorescent nanodiamonds, achieving cellular resolution (4.88 m) with a precision of 0.49 (minimum precision, 0.18 ) within a 0.28 mm2 field of view. We demonstrated temperature mapping of multiple brain depths in head-fixed and vigorously behaving mice subjected to nociceptive stimulation, detecting lower temperatures during anesthesia compared to the awake state in ventromedial hypothalamic nucleus (VMH) at a 5 mm depth. These mappings reveal that spatio-temporal temperature distribution and its anesthesia-dependent reduction are heterogeneous rather than uniform in VMH. This endomicroscopy provides a promising platform to dissect how deviations in biophysical parameters modulate deep-brain function.

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Imamura, R., Nakane, Y., Kataoka, N., Abe, H., Ohshima, T., Sotoma, S., Sugi, T.. 2025-11-29. Deep-brain thermo-endomicroscopy. https://doi.org/10.1101/2025.11.25.690615

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